BJ,
it could be a master cylinder if you have no fluid loss.  I would check
your fluid level first.  If it is low then you have a leak probably a
burst metal line somewhere in the front of the van.  Adding fluid and
pumping the brakes will reveal it's location.  Metal brake lines get
rusty and can fail.  You should visually inspect them about once a
year.  Let me know if I can help you further.

Ken Wilford
John 3:16
www.vanagain.com

BJ Feddish wrote:
> I went to GGB4 over the past weekend. I was happy that I got 21 MPG round
> trip and that included plenty of mountain climbing in 2nd and brake fade on
> the way down.
>
> Anyway, 1 mile from my house yesterday I almost rear ended a pickup truck as
> my brake pedal went all the way to the floor. Pumping did not help. My pads
> and shoes are less than a year old and the system was bled a month ago.  I
> left a message at my mechanics to fix this but is this most likely the
> master cylinder on it's way out? Should I pick one up at Bus Depot before
> bringing the van over? Is this something I can replace myself?
>
> Thanks,
> Bryan
>
>